Probably the best known and most wide-spread climate membrane - and admittedly the most breathable and water-proof one. It is a thin, water- and wind-proof foil made from Teflon (Polytetrafluorethylene, PTFE) applied to a carrier material. Breathability is achieved through micropores in the Teflon material 700 times the size of a water molecule and 20,000 times smaller than a drop of water. In a best case scenario, Gore-Tex is water-proof to a column of water 80 meters high. It is utilized as Two- or Three-layer laminate or as Z-Liner with other materials. See Three-layer laminate, Gore.